^^^ so then, about as long ago as push rod engines in general were designed...

look, its cool and all, and i can't back what im about to say with knowledge, cause i don't have any, but it seems to me there are gains to be had with OHC, and GM seems to ignore those possibilities on their big displacement motors (save for ZR1 in 90's).

OHC's weigh more, cost more, take up a lot more real estate under the hood, and don't provide any real benefit with the advent of variable valve lift/duration technology (the "cam in cam"). The GM LS family has had the highest specific outputs (HP/L) and actual ouputs of any V8 for the last ~10 or so years for a reason...

Now... give me that engine in the 4.8L displacement with the short stroke/big bore combo, shove it into the new Caprice and give it 3 pedals with 6 forward gears, and LSD and I'll be the first motherberkeleyer in line to buy it.

wvumtnbkr wrote:
For one, it would make the engine larger. Those cams have to go somewhere.
There was actually a pretty good thread about exactly this topic a few weeks ago. If you search for OHC, you will probably find it.
Rob

the ZR1 C4 was exactly that experiment. The pushrodded motor could manage a much larger displacement for the same engine size, so no net sacrifice of power per pound, power per dimension, power per fuel. In other words, to manage the same hp figure, the OHC cam engine GM would hypothetically design would be heavier, bigger but have less cubic inches of displacement.

Bobzilla wrote:
Now... give me that engine in the 4.8L displacement with the short stroke/big bore combo, shove it into the new Caprice and give it 3 pedals with 6 forward gears, and LSD and I'll be the first motherberkeleyer in line to buy it.

Bobzilla wrote:
Now... give me that engine in the 4.8L displacement with the short stroke/big bore combo, shove it into the new Caprice and give it 3 pedals with 6 forward gears, and LSD and I'll be the first motherberkeleyer in line to buy it.

Why would you want less displacement?

even with the smaller displacement it would still be 350hp, but less cubes to feed would be more highway economy.

Javelin wrote:
In reply to jmthunderbirdturbo:
OHC's weigh more, cost more, take up a *lot* more real estate under the hood, and don't provide any real benefit with the advent of variable valve lift/duration technology (the "cam in cam"). The GM LS family has had the highest specific outputs (HP/L) and actual ouputs of any V8 for the last ~10 or so years for a reason...

Not necessarily doubting this one, as i really don't know...

But even over some of the nutso German V8s? I could have sworn the Audi 4.2 is beyond the GM LS family, at least in terms of hp/L. (Which who cares... it's ricer math... just curious. )

wvumtnbkr wrote:
For one, it would make the engine larger. Those cams have to go somewhere.
There was actually a pretty good thread about exactly this topic a few weeks ago. If you search for OHC, you will probably find it.
Rob

the ZR1 C4 was exactly that experiment. The pushrodded motor could manage a much larger displacement for the same engine size, so no net sacrifice of power per pound, power per dimension, power per fuel. In other words, to manage the same hp figure, the OHC cam engine GM would hypothetically design would be heavier, bigger but have less cubic inches of displacement.

However, those ZR1's woke up much faster than the comparable tpi once lingenfelter got ahold of them. The LT5 was honestly better than the lt-1. I like the lt5 cars......I really do. I like the lsx cars as well, the experiment produced a great engine that should have been continued.